Apparatus for the prevention of incrustations and corrosion on metallic surfaces



F. HAUPTVOGEL APPARATUS FOR THE PREVENTION OF INCRUSTATIONS A Sept. 3, 1929.

CORROSION ON METALLIC SURFACES Filed April l'7. 1925 Patented Sept. 3, 1929.

UNITED STATES PATENT OFFICE.

FRIEDRICH HAUPTVOGEL, OF VIENNA, AUSTRIA.

SURFACES.

Application filed April 17, 1925, Serial No. 23,993, and in Belgium Kay 10, 1924.

The invention relates to the prevention of incrustation and corrosion in steam boilers, condensers and like apparatus.

Methods exist for electrically preventing the formation of incrustation and corrosion in steam boilers, condensers and other similar vessels. Such methods consist essentially in including the boiler or other vessel to be protected in an electric circuit. They are all based on the recognition that the formation of incrustation and corrosion in boilers, etc. is to be attributed to the fact that the impurities separating as a result of the vaporization of the water are deposited 1n the state of solid incrustation on the walls of the boiler under the action of electric currents fortuitously occuring inside the boiler,

from a variety of causes including possibly internal electrolytic action. In order-to attempt to neutralize the action of these fortuitous electric currents, a direct current is sent through the boiler, etc. which thus tends to prevent the deposit of such incrustin materials and corrosion.

2 Ilowever these previous methods have for various reasons not given satisfactory results. Suchknown methods, consisting for example in causing a direct current to pass by means of electrodes through the water so of the boiler, necessitate drilling the wall of theboiler, etc. at at least two points for the introduction of electrodes. It is obvious that such holes must be made water-tight, with v due regard to the steam pressure, and must moreover be provided with electric insula tion, which renders the a plication' of the method appreciably complicated and costly, especially when it is considered that the electrodes, in particular the anode is used up 40 ra idly and must therefore be renewed after re atively short service.

In carrying out the invention, the boiler or other vessel to be protected is mounted in a separate constantly loaded circuit,

branched from the two leads of a main electric supply network, the boiler being mounted in parallelwith a variable resistance serving to determine the strength of the necessary current. Measures are moreover taken to indicate immediately faults due to earthing occurrin in the mains.

Figure 1 of the drawing shows diagram- Figure 4 illustrates the connection of a signal lamp in both positive and negative leads.

vFig. 1 of the annexed drawing shows diagrammatically this new method of placing in circuit the boiler to be protected as well as the disposition of the resistance for obtaining a suitable current strength and potential. The boiler to be protected is designated K, and is mounted in a shunt circuit branched at a and bfrom the main network. In this circuit is included between a, and I), a variable resistance W enabling the above mentioned regulation of the necessary drop of potential. There is also rovided in each lead of the circuit a fuse S and in one of them a lamp L or other signalling device serving to indicate normal functioning of the installation.

However with this circuit arrangement, it is possible that in the event of grounding of one or the other of the conductors of the main network, the arrangement would be inoperative although the signal lamp is lighted; If for example, as shown in Fig. 2, the positive conductor of the network is grounded, there is established, besides the arranged operative circuit, a second circuit passing by b, the earth, the boiler K connected electrically to earth,-then by (1 S and a. But as no resistance is included in such additional circuit, there is immediately produced by this path a short circuit, such that the fuse S melts and the signal lamp receiving current, becomes ex-' 7 L, no longer tinguishe However this is the least dangerous case, as the extinction of the signal tlamp draws attention to the derangemen It is quite otherwise when the grounding is not complete, i. e; the circuit still is partly err melting of the fuse S,. but is sufficient to make the installation inoperative. Practice has shown that the electric currents which are formed within the boiler can only be neutralized by currents of the approximately same strength. If the strength of the current passing through the boiler is too great, the apparatus becomes inoperative. However the lamp L continues in such case to burn, provided the two fuses S and S remain intact.

The same conditions occur in Fig. 3, wherein the negative pole is grounded. In this case, the melting of the fuses does not occur at all, as the lamp is in series with the boiler and the grounded conductor. However in this case the current passing through the boiler is too heav and ino erative when.

the attention of the personnel is drawn to the derangement Which has occurred.

What I claim is:

1. In an apparatus for protecting metallic surfaces against incrustations comprising 3 a direct current circuit, a shunt circuit derived from said direct current circuit, which shunt circuit contains in series constant resistances in the form of incandescent lamps and an adjustable resistance and a second 4 shunt circuit derived fromsaid adjustable resistance and containing said surface to be protected.

2. In an apparatus for protecting metallic surfaces against incrustations comprising 4 a direct current source of supply, a circuit in shunt with said direct current source of supply comprising a plurality of constant resistance elements in series, a second circuit in shunt with said first shunt circuit and 5 connected at one of its t-erminals to one of said resistance elements by adjustable means to selectively adjust the pointof connection with such resistance element, said second shunt circuit containing the surface to be protected. F

In testimony whereof I have signed my name to this specification.

FRIEDRICH HAUPTVOGEL. 

